The present invention relates to a vaporizing apparatus for use in, for example, producing semiconductors. More specifically, the present invention relates to a vaporizing apparatus which is used to convert a liquid into a vapor and introduce the vapor into a processing chamber.
In recent years, in producing semiconductors, there has been an increasing demand for an apparatus for heating and vaporizing a liquid material, such as TEOS (tetraethoxysilane), a copper (I) compound or DMAH (dimethyl aluminum hydride), and stably supplying the vaporized material to a processing chamber. To control the supply of the material, a liquid pump and a liquid flowmeter are used. For example, a liquid material is controlled by a liquid flowmeter so as to flow at a predetermined flow rate, vaporized in a vaporizing apparatus and supplied to a processing chamber.
As an example of the vaporizing apparatus, there can be mentioned a vaporizing apparatus described in U.S. Pat. No. 5,553,188. In this vaporizing apparatus, a plurality of disks are provided in a stacked configuration, and a liquid is forced into and vaporized in the gaps between the disks. This vaporizing apparatus is small in size and enables vaporization with a satisfactorily high efficiency. However, the disks are pressed with a large force in order to achieve a high efficiency of vaporization, so that the vaporizing apparatus must be used in combination with a liquid pump capable of generating a high pressure. Consequently, the system is large and costly. Further, when the supply of a material is stopped, material remaining between the disks is subject to a change in properties, leading to clogging between the disks.
On the other hand, U.S. Pat. No. 5,520,001 discloses a vaporizing apparatus wherein a liquid material is vaporized in a small gap which is formed by a control valve body having a variable degree of opening, so as to control a rate of vaporization of the liquid material. However, a surface area for contact with the liquid in the above-mentioned gap is limited, with the result that vaporization efficiency is low.
In view of the above, the present invention has been made. It is an object of the present invention to provide a vaporizing apparatus which is small in size and enables vaporization of a liquid material with a satisfactorily high efficiency, and which limits the amount of material remaining after a vaporization operation.
According to the present invention, there is provided a vaporizing apparatus comprising:
a supply opening for supplying a liquid material;
a disk provided for covering the supply opening;
a discharge opening for discharging a vapor obtained by vaporizing the liquid material; and
an actuator for arbitrarily controlling a gap between the disk and the supply opening in accordance with a desired rate of vaporization.
By this arrangement, the gap between the disk and the supply opening can be arbitrarily controlled by the actuator, so that the rate of vaporization of the liquid material can be appropriately controlled.
The foregoing and other objects, features and advantages of the present invention will become apparent from the following detailed description and appended claims read in conjunction with the accompanying drawings.